Geopolitical disruptions and maritime transitions: Environmental and economic costs of rerouting

This study examines the environmental, operational and economic implications of crisis-induced rerouting in maritime shipping, focusing on the 2024 Red Sea crisis as a case study. Contributing to the literature by linking operational modelling with transition theory, offering new insights into how geopolitical crises can accelerate or constrain sustainability transitions in global shipping. Within the socio-technical transitions framework, it explores how landscape-level geopolitical disruptions interact with regime inertia and create opportunities for niche innovation. Using an activity-based bottom-up model integrated with AIS data, the study quantifies GHG emissions, costs and voyage durations for vessels rerouting via the Cape of Good Hope, covering three major Eurasian routes (Asia–West Europe, Asia–West Mediterranean, and Asia–East Mediterranean). Emissions cost analysis is combined with scenario modelling to assess trade-offs between environmental and economic impacts across different innovation pathways. Results show that rerouting increases GHG emissions at least 46 %, economic cost at least 51 % of entire route fleet and extends round-trip durations by 20–34 days. Despite this, most shipping companies increased vessels’ speeds, reflecting institutional inertia that prioritises short-term efficiency over sustainability. Scenario simulations reveal that incremental innovations (e.g. operation optimisation) reduce excess emissions by 8–10 %. Whereas, transformative innovations such as LNG fuel and shore power cut emissions by up to 23 %, with combined deployment achieving up to 33 % reductions. These findings highlight the limited impact of incremental measures under sustained disruption and underscore the potential of transformative innovations to accelerate sustainability transitions in global shipping.